Next update: both IBM-CPUs are 386!
Tested with a FIC-386SC, Rev. A3. Both work at 33 MHz, no one work at 40 MHz. Identified by CheckCPU as "standard 386"; identified by Speedsys as 80386DX (not sure about the correctness of this, maybe they are DX, or maybe SX).
In generally, they seems to be "nothing special".
Another test with a FIC-386-HC-HG, Rev. B, was not able to start both IBMs. Sadly, after that, no one more boot with every other 386-CPU is possible on this board (the IBMs still boot on the 386SC, so maybe the HC-HG has another problem).
Next thing is: few hours ago somebody brought me a desoldered IBM-chip in more or less bad condition, no idea is it working or not. Fortunately, all pins are present.
Is this maybe an IBM Blue Lightning BL2-BL3? Can the original frequency be recognized by the imprint?
Here Creating a voltage regulated 386 BL3 module from existing parts and here Re: 3 (+3 more) retro battle stations they are shown similar chips.
Compared to an adapter PGA-132 to QFP-132 with AMD-386DX-40, this IBM-chip is smaller, so it maybe can not be soldered instead of the AMD-CPU on the same adapter. And, of course, the number of the pins is different.
Are they other (smaller) adapters ecpecially for this IBM-chip on the market?